Ion-exchange chromatographic determination of hypoglycin A in canned ackee fruit

An ion-exchange chromatographic method was developed to determine hypoglycin A (HG-A) levels in canned ackee fruit by using an amino acid analyzer. HG-A was extracted by homogenizing the sample in 80% alcohol. An isocratic buffer system, consisting of 30% sodium citrate buffer (pH 3.15) and 70% sodium chloride-sodium acetate buffer (pH 7.40) was used to obtain baseline separation between HG-A and the other amino acids. The system can detect HG-A levels as low as 4.8 micrograms/mL. HG-A levels in the edible portion of fruit in 6 cans ranged from 11.0 to 66.5 mg HG-A/can. Recoveries by standard addition averaged 102.5%.     

Triticale,wheat, and rye growth rates and mineral accumulation at various growth stages

Abstract

Cultivars of triticale, wheat, and rye were grown with different N‐fertilizer rates and sampled at various maturity stages in 1975 to 1977. ‘6TA 131’ triticale, ‘Arthur’ wheat, and ‘Abruzzi’ rye were used as checks. Increasing N fertilizer rates increased dry matter and N accumulation in the above‐ground plant parts. However, after flowering losses of dry matter and N from the plants increased with N fertilizer rates. Triticale and rye generally absorbed more N from the soil than wheat. Triticale and wheat straw had higher P concentrations than rye. The head/straw concentration ratios were: triticale and rye>wheat for P, wheat>triticale and rye for K while Ca and Mg ratios were triticale>wheat>rye.     

Phytoestrogen content of beverages, nuts, seeds, and oils

Phytoestrogens are secondary plant metabolites that have received increasing attention for their bioactivity, in particular due to their structural and functional similarity to 17beta-estradiol. Although urinary and plasma phytoestrogens can be used as biomarkers for dietary intake, this is often not possible in large epidemiological studies or in the assessment of general exposure in free-living individuals. Accurate information about dietary phytoestrogens is therefore important, but there are very limited data concerning food contents. In this study was analyzed a comprehensive selection of tea, coffee, alcoholic beverages, nuts, seeds, and oils for their phytoestrogen content using a newly developed sensitive method based on LC-MS incorporating (13)C 3-labeled standards. Phytoestrogens were detected in all foods analyzed, although the contents in gin and bitter (beer) were below the limit of quantification (1.5 microg/100 g). Lignans were the main type of phytoestrogens detected. Tea and coffee contained up to 20 microg/100 g phytoestrogens and beer (except bitter) contained up to 71 microg/100 g, mainly lignans. As these beverages are commonly consumed, they are a main source of dietary lignans. The results published here will contribute to databases of dietary phytoestrogen content and allow a more accurate determination of phytoestrogen exposure in free-living individuals.     

Growth,yield and fruit quality of cherry tomato irrigated with saline water at different developmental stages

Water shortage is a serious environmental and agricultural problem and saline underground water has been widely used to make up the fresh water shortage in northwestern China. An open-field experiment was conducted to establish a proper irrigation scheme with saline water for cherry tomato in the Minqin oasis, where very severe salinization occurs. The experiment had four treatments including fresh or saline irrigation over the crop season (control, C, T3), fresh/saline-water irrigation change on days after thinning 50 (DAT 50, T1) and saline/fresh irrigation change on DAT 50 (T2). Leaf area index (LAI), photosynthesis rate (P_n), transpiration rate (T_r), leaf dry matter (LDM), stem dry matter (StDM), yield, marketable fruit and total soluble solids (TSS) of tomato were measured. Saline irrigation, irrespective of the timing, significantly decreased maximum LAI, LDM and StDM, P_n, T_r and stomatal conductance but significantly stimulated water use efficiency. The reduction in maximum LAI, LDM and StDM was lower in T2 than in T1 and T3. Harvest index (HI) and TSS were higher in T2 and T3 than in T1 and C. Marketable fruit had no significant change in T2 but significantly declined in T1 and T3. Maximum saturated soil conductivity without yield reduction (the salt tolerance threshold) was 3.69?dS m^?1. Total yield of tomato would decrease by 9.85% with one unit increase of soil salinityhigher than the threshold. Final yield significantly reduced by 24.6% and 23.1% in T1 and T3 treatments, respectively. Our results suggest that irrigation with saline water before DAT 50 and fresh water after DAT 50 should be advocated for cherry tomato plantation in water-scarce areas like the Minqin oasis.     

Foliar potassium,calcium, magnesium,zinc, and manganese content in soybean cultivars at different stages of development

Plant tissue accumulation of potassium (K), calcium (Ca), magnesium (Mg), zinc (Zn), and manganese (Mn) was determined for six soybean [Glycine max (L.) Merr.] cultivars at successive stages of development. No nutrient accumulation patterns among the cultivars were found. The results obtained showed that the highest concentrations of K were found at the vegetative stage (V) and the lowest towards the end of the life cycle of the plant (R55). By contrast, Ca was lowest at the vegetative stage while increasing in the leaves in later growth stages. No significant differences in Mg content were found between growth stages. Manganese levels were lower at R2 and R4 than at R55 stages of growth with an accumulation towards the end of the reproductive cycle. Changes in Zn content between stages were different for each cultivar. The differing behavior of these elements is related to the difference in their mobility and transport capacities within the plant.     

Yield and quality of pectins extractable from the peels of thai mango cultivars depending on fruit ripeness

Pectins, recovered from the peels of four mango ( Mangifera indica L.) cultivars by mimicking industrial techniques, were evaluated in terms of yield, composition, macromolecular properties, and technofunctional quality. Freeze-dried peels of mature-green fruits, after major mesocarp softening, and at full ripeness were extracted using hot acid. The pectins were precipitated in propan-2-ol and their crude yields quantified as alcohol-insoluble substance. Like apple pomace, the dried peels provided hardly acetylated (DAc < 6.3%) rapid-set to ultrarapid-set high-methoxyl pectins at starch-adjusted yields of 11-21 g/100 g. However, despite similar high molecular weight fractions and galacturonic acid/rhamnose ratios, their average molecular weight was markedly reduced by a characteristic, almost monodisperse fraction of 16000-19000. Expanded galactans, indicated by galactose/rhamnose ratios of 15-24 mol/mol, probably represented arabinogalactan side-chain fragments withstanding hot-acid extraction at pH 1.5 and 2.0, as implied by arabinose/galactose ratios of 8-15 and 33-56 mol/100 mol, respectively. Limited galacturonic acid contents made the mango peel pectins less valuable than commercial apple pectins with regard to gelling capacity and thickening properties. Whereas starch and matrix glycan fragments almost completely degraded during ripening, depolymerization of pectins and galactans was insignificant. Technofunctional properties, modulated by extraction at different pH values, were ascribed to structural differences influencing macromolecular entanglements.     

桂西北不同植被恢复阶段土壤氨氧化细菌遗传多样性研究

以桂西北喀斯特不同植被恢复阶段(草丛、灌木林、次生林、原生林)生态系统为研究对象,运用分子生物学技术分析了土壤氨氧化细菌amoA功能基因多样性,探讨了其与脲酶活性和土壤理化性质的关系.结果显示,随着植被的恢复,土壤氨氧化细菌多样性指数与均匀度指数呈增大趋势(灌木林例外),且土壤中氨氧化细菌群落结构发生了改变:主要表现在因Nitrosospira3簇种群对铵态氮浓度敏感度差异导致其在3a、3b簇中分布不一致;相关分析表明;土壤脲酶活性与铵态氮浓度呈正相关关系,土壤脲酶可能通过影响铵态氮浓度改变氨氧化细菌多样性,但植被恢复后期土壤铵态氮浓度减少并未降低土壤氨氧化细菌多样性.LIBSHUFF和RDA分析揭示,植被类型和土壤脲酶活性及pH与氨氧化细菌群落结构紧密相关,说明植被和土壤氮素有效性以及pH可能是决定土壤氨氧化细菌多样性的主要因子,为深入理解喀斯特地区土壤氮素循环提供了一定的科学依据.     

基于多生育期光谱变量的水稻直链淀粉含量监测

直链淀粉含量是评价稻米品质的重要指标之一,其累积生长过程是多生育期、多因素综合作用的结果。为了探究多生育期信息引入对水稻籽粒直链淀粉含量监测模型的影响,实现水稻品质信息的大规模准确监测。该研究选取水稻孕穗期、抽穗期、灌浆期和成熟期这4个有关水稻籽粒形成发育的生育期的冠层光谱,分析原光谱、植被指数、高光谱特征参数,及其变换形式与水稻籽粒直链淀粉含量的相关性,筛选得到相关性较好的光谱变量,并利用逐步回归的方法进行建模,建立基于多生育期光谱变量的直链淀粉含量预测模型。结果表明：一阶导数、差值植被指数（Difference Vegetation Index, DVI）、比值植被指数（Ratio Vegetation Index, RVI）及成熟期特征参数表现出较高敏感性,最适用于直链淀粉含量预测的生育期为成熟期,而多生育期信息的综合利用能显著提高模型预测精度,最佳多生育期预测模型为孕穗-抽穗-成熟期组合模型,建模决定系数（Coefficient of Determination, R2）为0.708,均方根误差（Root Mean Square Error, RMSE）为0.711%,平均绝对百分比误差（Mean Absolute Percent Error, MAPE）为3.22%,验证R2为0.631,RMSE为0.768%,MAPE为3.99%,证明该模型能较为精确地预测籽粒直链淀粉含量,为稻米品质指标大尺度统计监测提供一定的技术支撑和应用基础。     

Volatile composition of coffee berries at different stages of ripeness and their possible attraction to the coffee berry borer Hypothenemus hampei (Coleoptera: Curculionidae)

The analysis of volatile emissions of coffee berries in different physiological states of ripeness was performed using dynamic headspace and gas chromatography/mass spectrometry analysis for Coffea arabica, var. Colombia. The composition of the volatiles emitted by coffee berries is dominated by very high levels of alcohols, mainly ethanol, in all stages of ripeness in comparison with other compounds. Overripe coffee berries have high volatile emissions and show a composition dominated mainly by esters followed by alcohols, ketones, and aldehydes. The lowest level compounds were monoterpenes. 2-Methyl furan was detected in various ripening stages; this compound has not been previously reported as a coffee berry volatile. The presence of ethanol and other alcohols in the volatile composition might explain the effectiveness of using traps with mixed alcohols for detection and capture of coffee berry borers.     

Identification of volatile compounds in cantaloupe at various developmental stages using solid phase microextraction

Using an automated rapid headspace solid phase microextraction (SPME) method for volatile extraction in cantaloupes, 86 compounds already reported for muskmelons were recovered and an additional 53 compounds not previously reported were identified or tentatively identified. The SPME method extracted a copious number of volatiles that can be analyzed to clearly differentiate between variety, growth stage, and stage of harvest ripeness. Most of the newly reported compounds in cantaloupe were esters and aldehydes that have already been demonstrated as flavor-related compounds in other products. All esters believed to have flavor impact increased progressively after pollination, and this trend continued with increasing harvest maturity. However, compound recovery often decreased when fruits were harvested over-ripe. Most aldehydes increased during early growth stages and then tapered off with increasing harvest maturity. The SPME method suitably recovered most compounds reported to impart characteristic flavor/aroma in muskmelons. SPME offers experimental flexibility and the ability to discover more compounds and address flavor quality changes in fresh-cut cantaloupe.     

Folate content in strawberries (Fragaria x ananassa): effects of cultivar,ripeness, year of harvest,storage, and commercial processing

Folate concentrations in strawberries and folate retention during storage and commercial processing of strawberries were investigated. No previous study has focused on the effects of cultivar, ripeness, and year of harvest of strawberries with respect to the folate content. This study showed the folate concentration in strawberries to significantly depend on all of these different factors. Total folate was quantified using a modified and validated radioprotein-binding assay with external calibration (5-CH(3)-H(4)folate). Folate content in 13 different strawberry cultivars varied from 335 microg/100 g of dry matter (DM) for cv. Senga Sengana to 644 microg/100 g of DM for cv. Elsanta. Swedish harvests from 1999 and 2001 yielded higher folate concentrations than did the harvest from 2000, and the grade of ripeness affected the folate content in strawberries. This study indicated high folate retention in intact berries during storage until 3 or 9 days at 4 degrees C (71-99%) and also in most tested commercial products (79-103%). On the basis of these data fresh strawberries as well as processed strawberry products are recommended to be good folate sources. For instance, 250 g (fresh weight) of strawberries ( approximately 125 microg of folate) supplies approximately 50% of the recommended daily folate intake in various European countries (200-300 microg/day) or 30% of the U.S. recommendation (400 microg/day).     

Identification of volatile compounds in soybean at various developmental stages using solid phase microextraction

Soybean (Glycine max) seed volatiles were analyzed using a solid phase microextraction (SPME) method combined with gas chromatography-mass spectrometry (GC-MS). Thirty volatile compounds already reported for soybean were recovered, and an additional 19 compounds not previously reported were identified or tentatively identified. The SPME method was utilized to compare the volatile profile of soybean seed at three distinct stages of development. Most of the newly reported compounds in soybean seed were aldehydes and ketones. During early periods of development at maturity stage R6, several volatiles were present at relatively high concentrations, including 3-hexanone, (E)-2-hexenal, 1-hexanol, and 3-octanone. At maturity stage R7 and R8, decreased amounts of 3-hexanone, (E)-2-hexenal, 1-hexanol, and 3-octanone were observed. At maturity stage R8 hexanal, (E)-2-heptenal, (E)-2-octenal, ethanol, 1-hexanol, and 1-octen-3-ol were detected at relatively high concentrations. SPME offers the ability to differentiate between the three soybean developmental stages that yield both fundamental and practical information.     

Tracking hypoglycins A and B over different maturity stages: implications for detoxification of ackee (Blighia sapida K.D. Koenig) fruits

Consumption of improperly ripened ackee ( Blighia sapida K.D. Koenig) often results in fatalities. The causal toxin, hypoglycin A, decreases in the edible arilli upon maturity; regulation of hypoglycin A in the arilli is thus critical. Hypoglycin B, also toxic, is confined to the seeds. Hypoglycins A and B were tracked in ackees grown in Jamaica over different maturity stages using RP-HPLC. Studies on the 'Butter' and 'Cheese' ackee varieties and across two different harvest seasons were conducted. In 'Cheese' ackees, hypoglycin A decreased from about 8000 mg/kg in the green arilli and seeds to 271 and 1451 mg/kg, respectively, in the ripe fruit whereas hypoglycin B levels in the seeds increased from 1629 to 11774 mg/kg. The strong inverse relationship demonstrated that hypoglycin B in the seeds serves as a sink for hypoglycin A from the ripening arilli and is thereby involved in the detoxification mechanism of the fruit.     

水分胁迫对日光温室葡萄叶片生理变化及果实发育的影响

为探究鲜食日光温室葡萄高效节水生产的水分管理方式,选取日光温室6a生葡萄‘红地球’为试验材料,以充分灌溉为对照[CK,土壤含水率为75%～100%的田间持水率(θf)],分别在萌芽期、新梢生长期、开花坐果期、果实膨大期、着色成熟期设置土壤含水率为55%θf(其他4个生育期为75%～100%θf)的5个水分胁迫处理,调查叶片超氧化物歧化酶(SOD)活性及膜质过氧化物丙二醛(MDA)和脯氨酸(Pro)含量、果实纵横径、果实硬度、单粒重量和产量,研究日光温室葡萄叶片生理和果实产量对水分胁迫的响应机制。结果表明,在果实膨大期、着色成熟期施加水分胁迫均会显著降低葡萄叶片SOD活性和Pro含量,导致MDA含量大量积累,对叶片产生不利影响。在萌芽期、新梢生长期、开花坐果期进行水分胁迫对葡萄叶片SOD活性、Pro含量影响不大,但对叶片MDA含量的影响具有滞后效应。果实膨大期水分胁迫葡萄产量仅为14 830kg·hm–2,较CK和萌芽期、新梢生长期水分胁迫显著减产20%以上。因此,水分胁迫显著降低果实膨大期SOD活性及渗透调节物质含量,增加膜质过氧化物含量,并导致产量降低,该时期不宜进行亏水处理;生长前期的水分胁迫对葡萄叶片的生理和果实的影响不显著。     

甜菜生育期叶面营养调节对其产量和含糖率作用的研究

为提高甜菜的含糖量,设置了甜菜不同生育阶段叶面喷施营养液提高其含糖量的效果试验。两年田间试验结果表明:叶丛快速生长期,以喷施KH2PO4+ZnSO4或KH2PO4+MgSO4营养液作用显著,增产8.88%~9.30%,提高含糖率0.51~0.55个百分点(糖度),增加产糖量12.53%~13.25%;块根及糖分增长期,以喷施KH2PO4+Na2B4O7或KH2PO4+MnSO4营养液作用显著,增产5.89%~6.90%,提高含糖率0.85~1.04个百分点(糖度),增加产糖量12.31%~12.39%。其增产、增糖处理之作用与提高其光合性能,改善氮、磷和核酸营养水平,促进叶丛中糖分的积累与转化等有关,从而有利于块根的增长和糖分积累。为此,甜菜生育前期喷施KH2PO4+ZnSO4和生育后期喷施KH2PO4+Na2B4O7,是提高甜菜产量和含糖率的有效途径之一。     

Changes in esculeoside A content in different regions of the tomato fruit during maturation and heat processing

We previously demonstrated that esculeogenin A, a new aglycone of the tomato sapogenol esculeoside A, inhibits both acyl coenzyme A:cholesterol acyl-transferase (ACAT)-1 and -2 and ameliorates the pathogenesis of atherosclerosis in apoE deficient mice. Although we believe that daily intake of esculeoside A from tomato products can play a beneficial role in preventing the pathogenesis of atherosclerosis, the compound is not being used for preventive medicine due to the lack of information on methods for quantitative analysis and the content and stability of the compound in tomato products. In the present study, we report the development of a high-performance liquid chromatography (HPLC) method using an instrument equipped with a refractive index (RI) detector for esculeoside A quantification. We used this method to measure the changes in esculeoside A content during maturation, its distribution in the fruit body, and its stability during the heating process. The contents of esculeoside A in cherry tomatoes and Momotaro tomatoes were 21- and 9-fold, respectively, higher than that of lycopene, which is the most well-known compound in tomatoes. Furthermore, the esculeoside A content in pericarp wall was higher than in the whole tomato fruit and increased in a time-dependent manner during maturation. Although the melting point of purified esculeoside A was 225 °C, the esculeoside A in crude tomato extract decreased in a temperature-dependent manner. Degradation due to the heating process was inhibited under a pH of 9. These results demonstrated that the esculeoside A content differs in the various types of tomatoes, during maturation, and during the heating process used for preservation.     

Influence of cultivar and fruit ripening on olive (Olea europaea) fruit protein content, composition, and antioxidant activity

Proteins of olive fruit mesocarp are not very well-known at present. However, they have been shown to pass, at least partially, to the olive oil during its elaboration and therefore might be contributing to some of the special characteristics of this vegetable oil. In this study, protein content and composition were determined in olive fruits, cv. Arbequina and Picual, at three stages of ripening: green, spotted, and purple. Mesocarp proteins constituted 1.3-1.8% of the dry weight of the olive fruit, and cultivar and fruit ripening did not produce important changes in mesocarp protein content or composition. In addition, this composition was also similar to the amino acid composition of a 4.6-kDa polypeptide, which is the major protein component of olive oils and of oil bodies of olive fruit mesocarp, suggesting that this polypeptide is likely to be a major component of mesocarp proteins. There was, also, a relationship between the oil content of the olive fruit and the protein content determined, suggesting a stabilizing function of these proteins in the oil bodies of the olive fruit, analogously to the role suggested for oleosins. This stabilizing function does not seem to be extended to olive oils because when the polypeptides isolated were added at 20 ppm to soybean oil, the stability of the oil increased only slightly, suggesting that if these compounds play some role in the stability of the oils, this should be mostly a consequence of the possible interactions among these protein components and other olive oil antioxidant constituents.     

不同生育期调亏灌溉对酿酒葡萄耗水及果实品质的影响

不同程度的土壤干旱对酿酒葡萄的果实品质、产量和水分利用效率具有显著影响。明晰不同生育阶段干旱胁迫效应对酿酒葡萄土壤水分精准化管理和节水灌溉方案的制定具有重要的意义。本文于2014年在河西走廊中东部武威市凉州区清源镇威龙葡萄园产区开展了酿酒葡萄不同生育期、不同干旱胁迫程度的试验研究。在保持其他生育期土壤水分为正常灌溉(土壤水分阈值70%~75%)的情况下,在葡萄的萌芽期、抽蔓期、开花期、浆果膨大期和着色成熟期分别进行中度(土壤水分阈值60%~65%)和重度(土壤水分阈值50%~55%)的干旱处理,同时增设浆果膨大期的充分灌溉(土壤水分阈值80%~85%)处理,以全生育期的正常灌溉(土壤水分阈值70%~75%)作为对照,进行葡萄耗水特征和产量品质的测定。试验结果表明:不同处理土壤含水量垂直变化趋势一致,随土壤深度增加土壤含水量呈持续递增趋势;随着土壤深度递增,调亏灌溉对土壤含水量的影响越来越弱;40~60 cm土壤剖面,调亏处理含水量较对照减少幅度最大;浆果膨大期土壤剖面内含水量均低于其他生育期。不同处理酿酒葡萄耗水强度随时间变化趋势一致,萌芽期日耗水强度最小,为0.13~0.33 mm·d-1,而浆果膨大期耗水强度最大,为2.30~4.09 mm·d-1。萌芽期中度胁迫处理酿酒葡萄产量和水分利用效率最高,分别达到15 228 kg·hm-2和3.62 kg·m-3;浆果膨大期充分灌溉处理次之,而浆果膨大期重度胁迫处理最低,仅分别为7 128 kg·hm-2和2.26 kg·m-3。着色成熟期中度胁迫下,酿酒葡萄花青苷、还原糖、单宁、总酚含量比生育期正常供水处理高2.7%、6.56%、17.91%和23.23%,且有效抑制可滴定酸积累(P0.05),而其他处理与对照之间品质指标差异不显著。综合考虑产量、水分生产效率及果实品质等指标,最佳酿酒葡萄水分调控处理为着色成熟期中度胁迫,即着色成熟期土壤相对含水率为60%~65%、其余生育期土壤相对含水率为70%~75%。由此可见,在酿酒葡萄栽培时适时、适度的调亏灌溉既能显著提高水分生产效率,实现节水、高效用水的目的,又能提高果实品质,对河西走廊地区酿酒葡萄种植具有重要的意义。     

Isoflavone composition, phenol content, and antioxidant activity of soybean seeds from India and Bulgaria

Isoflavone levels and isoflavone chemical composition in 11 cultivars of soybean, including 4 Indian and 7 genotypes of soybean grown in Bulgaria, were analyzed as determined by C 18 reversed phase high-performance liquid chromatography coupled with a photodiode array detector. Antioxidant activity of soybean extracts was assessed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and total phenolic compounds (TPC) were determined by using Folin-Ciocalteu reagent. The range of total isoflavones (TI) was 558.2-1048.6 microg g (-1) of soy in Indian cultivars, and it was 627.9-1716.9 microg g (-1) of soy in the case of Bulgarian cultivars. The highest and lowest total isoflavone contents were observed for Maus-2 (1048.6 microg g (-1) of soy) and Hardee (558.2 microg g (-1) of soy), respectively, for the Indian cultivars, and they were observed for Boryara (1716.9 microg g (-1) of soy) and Line 5 (627.9 microg g (-1) of soy) for the Bulgarian genotypes. DPPH radical scavenging activity did not differ significantly among the cultivars and did not correlate with TI, whereas TPC correlated well with TI and weakly with DPPH. Malonylglucoside of all the aglycones, total genistein (TGin), and total daidzein (TDin) showed strong correlation with total isoflavones, whereas acetylglucoside and aglycone levels did not significantly correlate with total isoflavone. Profiling of soybean isoflavone is helpful in understanding the regulation of isoflavone biosynthesis for greater improved resistance of crops to disease and greater health benefits for humans. This comparative study of soybean cultivars grown in India and Bulgaria throws light on their composition and nutraceutical value.